In this study, the curves of variation of melting temperature as a function of pressure were determined for pressures up to 20 GPa using molecular dynamics (MD) calculations. The CLAYFF force field is used for the simulated PT curve of the clay kaolinite structure. For this purpose, we have adopted the Z-method to determine the melting point (Tm) and superheat limit temperature (TLS) for different densities in kaolinite clay. In addition, various quantities, such as the radial distribution function (RDF), the mean square displacement (MSD), and the diffusion coefficient were evaluated in order to ensure the solid behaviour at the superheat limit temperature and the liquid behaviour at the melting point for the equilibrated structure of kaolinite.

The structural and mechanical properties of dickite and nacrite are important in numerous scientific and industrial applications, but currently lacking in experimental data. To address this issue, numerical methods have been employed to quantify these properties. First, the interaction potential parameters for dickite and nacrite were determined using a relaxed fitting approach. Then, the properties were calculated with energy minimization. The results revealed that the interaction potential parameters and properties exhibit polytypic-specific dependence. When compared to available experimental and simulation data at zero pressure, such as lattice parameters, elastic constants, bulk modulus, and shear modulus, the calculated results are in good agreement, confirming the reliability of the numerical methods. In addition, properties challenging to determine experimentally, such as transverse and longitudinal wave velocities, dielectric properties, and piezoelectric constants, were also investigated, offering valuable contributions to the understanding of these kaolin polytypes.